Respuesta :

4(a+5)=4a+20

everything inside the parenthesis, so you are distributing (multiplying) the four to the a and the 5  
4(a+5) 

When using the distributive property, you have to distribute (multiply) the 4 to the a and then the 4 to the 5. It looks like this...

4(a) = 4a
4(5) = 20

Final Answer: 4a+20